As ammonium dihydrogen phosphate (ADP) is a popular nonlinear optical crystal, to engineer its linear and nonlinear optical properties, the chalcogenide compound cobalt sulphide (CoS) was doped and the crystals were grown by the slow solvent evaporation method. To increase the solubility of CoS in water, its nanoparticles were synthesized by wet chemical technique using ethylene diamine as the capping agent followed by microwave irradiation. The nanoparticle sample exhibited finite solubility in water and was used to dope in ADP crystals. The powder XRD patterns showed the single phase nature of the doped crystals. The FTIR spectra confirmed the presence of various functional groups and EDAX gave the estimation of Co and S elements. The EPR spectroscopy also confirmed the presence of cobalt in the doped samples. TGA indicated slightly less thermal stability of the doped crystals compared to the pure ADP. The dielectric study was carried out at room temperature in the frequency range from 100[Formula: see text]Hz to 1[Formula: see text]MHz. Also, various linear optical parameters were evaluated for pure and doped crystals using UV–Vis spectroscopy. The second harmonic generation (SHG) efficiency of Nd:YAG laser was evaluated by the Kurtz and Parry method for the doped samples, it was found to be slightly lesser than that of the pure ADP crystals.

No abstract

No abstract

Ammonium penataborate (APB) crystals are well known for their nonlinear optical (NLO) properties. Attempt is made to study the changes produced by addition of chalcogenide compound sodium sulphide in APB crystals. Di-sodium sulphide (Na2S) is soluble in water and its solubility is further increased for Na2S nanoparticles. The Na2S nanoparticles are synthesized by using co-precipitation method followed by microwave irradiation. The slow solvent evaporation method is used to grow pure and Na2S added APB crystals. Pure and Na2S added APB crystals possess orthorhombic crystal structure with the mixed phase nature for the Na2S added APB. The presence of sodium in APB is confirmed by AAS study. In FTIR spectra the absorption peak of S–H asymmetric stretching is observed for Na2S added APB indicating the presence of sulphur. The thermal stability of APB crystal is enhanced on doping the Na2S in it. The dielectric study is also carried out within this frequency range. The Jonscher’s power law is applied to AC conductivity data. The impedance spectroscopy study is carried out at room temperature within 100 Hz to 1 MHz frequency range. The complex impedance and modulus plots are drawn. The complex impedance plots indicate only the grain contribution. The Kurtz and Perry powder study indicates that all the crystals are exhibiting NLO properties with varying SHG efficiency.

No abstract